H.P Acthar Gel stimulate the adrenal cortex to secrete cortisol. Additionally H.P. Acthar gel is also reported to bind to melanocortin receptors. Melanocortin receptor activation has been shown to exert marked anti-inflammatory and immune-modulatory effects in animal studies, by modulating pro inflammatory cytokines, followed by induction of anti- inflammatory mediators and subsequent leukocyte migration. Specifically melanocortins down regulate Tumor Necrosis Factor (TNF) alpha, Interleukin (IL) -2, Interferon gamma and T-cell proliferation and upregulates IL-10 and regulatory T cells. For this reason H.P. Acthar is an approved treatment for ocular inflammatory disease.